1. Field of the Invention
The present invention relates to an optical device and a method of fabricating the same, and more particularly, to a light-condensing device and a method of fabricating the same.
2. Description of the Related Art
A Fresnel lens, ordinarily used as a light-condensing device, performs the same function as a convex lens but has a structure with reduced thickness, wherein a convex lens' surface is partitioned into concentric annular sections and arranged in a flat plane. The partitioned sections are referred to as Fresnel zones. At least one Fresnel zone located in the center is spherical.
In order to fabricate such a Fresnel lens, a mold having a profile corresponding to the Fresnel zones is cut from a mold plate using a diamond bite, and then the Fresnel lens is molded using the mold.
However, when using such a method, there is a limit to reducing the size of the Fresnel lens. If semiconductor technology was used to form the Fresnel lens, the size of the lens could be reduced, but it could be extremely difficult to form the spherical Fresnel zone using semiconductor processing technology.